1. Field of the Invention
The present invention relates to a card reader/printer capable of full duplex mark sense card reading and printing under microprocessor control.
2. Description of the Prior Art
The need exists for a low priced full duplex card reader/printer to serve as an input/output device for data processing systems in which input-data-responsive messages are printed. An example of the usefullness of such a device is in an inventory control system. Here, the user might have an individual card on which he can indicate the quantity of a certain item currently in stock. As this card is read into the system, a responsive message is written onto the same card which includes (1) a print-out of this current quantity, thereby providing immediate verification that the correct data has been entered, and (2) a printed indication of the item designation, the number of days supply remaining, and an indication that the item should be reordered.
In the past, considerable equipment was required to accomplish these tasks. For example, a typical prior art system required that each inventory entry be written on a data sheet which was then transferred to card format by a key punch operator using a card punch/verifier apparatus. The punched card then was fed into a card reader for data entry into the computor. The responsive message, if any, was provided as an entry on a printed data output sheet, or as a separately punched card. In both instances, there was considerable delay between input and output, and correlation between the data entry and the responsive output was difficult. In the case of a print-out, the user would have to scan many entries to find that one related to a certain product. In the case of punched card output, it was necessary to use a device which printed on the card the specific data punched therein. Again, additional equipment and time delay was involved. An object of the present system is to provide a full duplex card reader/printer which overcomes these shortcomings. One objective is to provide a reader that is capable of sensing both punched holes and opaque marks placed on the card. In this way, the data entry can be made directly onto the card, without the need for first marking a data sheet entry that is subsequently key punched. Thus, in an inventory system, a card can be partially prepunched to indicate a certain item. The person taking the inventory then can mark the current quantity directly onto the remaining portion of the card, using a marker pen or pencil.
A further object of the present invention is to provide a card reader/printer in which the printed message (a) can correspond to the data marked or punched on the card, so as to provide a verification function, (b) can be totally independent of the data entered on the card, or (c) can consist of a message that is generated in response to the data entered on the card. Another object of the present invention is to provide such a card reader/printer which operates under microprocessor control. In the illustrative inventory control system, the present invention may be programmed to print both a verification of the entered stock item and current quantity, and a dataresponsive message indicating the number of days supply remaining, together with an indication as to whether the product should be reordered.
Still a further object of the present invention is to provide a microprocessor-controlled card reader/printer that is capable of interfacing with another computer or data processing system. In the case of inventory control, the invention may interface with a larger computer used to perform the actual inventory accounting system. On-line operation is possible, so that data entered from the reader portion of the invention may be supplied via the microprocessor to the master system. Responsive data then can be relayed back for direct print-out by the reader/printer on the same data entry card. As an example of the usefulness of such an arrangement, the master system may keep track of the lead time required for the reorder of each item. This may change from day to day, depending on delays at the supplier, material availability and so forth. Thus, when a particular inventory entry card indicates e.g., that a 10 day supply of the item remains, the master computer may ascertain that eight days are required to reorder the item. The computer may then cause a responsive message to be printed directly onto the data card, indicating that the item must be ordered within the next two days.